I use fuseable beads and put them on a pegboard while looking at either a ripped sprite from a video game or custom sprites that have been made by me or other pixel artists. I usually use the program GIMP or Photoshop to grid the sprite, then make it, then iron it super flat so no holes show (which is the hardest part by far since you can over melt them quite easily and ruin them) and then Voila! It's done! ^.^